Substrates with a transparent electrode in which a conductive oxide thin-film of indium tin composite oxide (ITO) or the like is formed on a transparent substrate such as a transparent film or glass are widely used as transparent electrodes for displays and touch panels. The electric resistance and the light transmittance are main factors that determine the performance of a substrate with a transparent electrode, and one having low resistance and high light transmittance is desired in the market.
As a method for forming an ITO film having low resistance and high transparency, a method is widely used in which an amorphous ITO film is formed on a transparent film by a sputtering method, and then heated under an oxygen atmosphere, for example in the air, to crystallize the amorphous ITO.
It is preferable that the time required for crystallization by heating (annealing) is short from the viewpoint of productivity, and ITO that is easily crystallized has been desired heretofore. Patent Documents 1 and 2 disclose a method for producing a transparent conductive film which is easily crystallized by short-time heating. On the other hand, an amorphous conductive oxide thin-film may be desired depending on the use purpose of the transparent conductive film, and Patent Document 3 discloses a method for producing a transparent conductive film which is not easily crystallized.
Patent Document 4 describes a method for producing a transparent conductive film which can be crystallized at room temperature or a low temperature and thus high temperature heat treatment is required for crystallization.